How to add a link to the Next-Tube site.

For light background
Link to English version: <a href="http://www.next-tube.com/"> <img src="http://www.next-tube.com/pictures/nextt_l.gif" width="88" height="31" border="0" alt="Next-Tube. Design of vacuum tube audio and hybrid amplifiers."></a> Link to Russian version: <a href="http://www.next-tube.com/ru/"> <img src="http://www.next-tube.com/pictures/nextt_l.gif" width="88" height="31" border="0" alt="Next-Tube. Проектирование и моделирование ламповых аудиоусилителей и их узлов."></a>

For dark background
Link to English version: <a href="http://www.next-tube.com/"> <img src="http://www.next-tube.com/pictures/nextt_d.gif" width="88" height="31" border="0" alt="Next-Tube. Design of vacuum tube audio and hybrid amplifiers."></a> Link to Russian version: <a href="http://www.next-tube.com/ru/"> <img src="http://www.next-tube.com/pictures/nextt_d.gif" width="88" height="31" border="0" alt="Next-Tube. Проектирование и моделирование ламповых аудиоусилителей и их узлов."></a>